An identification method of orbit responses rooting in vibration analysis of rotor during touchdowns of active magnetic bearings. (3rd February 2018)

• Record Type: Journal Article
• Authors: Liu, Tao; Lyu, Mindong; Wang, Zixi; Yan, Shaoze
• Is Part Of: Journal of sound and vibration. Volume 414(2018)
• Page Start: 174
• Page End: 191
• Publication Date: 2018-02-03
• Subjects: Active magnetic bearings -- Touchdown bearings -- Touchdown -- Identification of the orbit response; Sound -- Periodicals; Vibration -- Periodicals; Son -- Périodiques; Vibration -- Périodiques; Sound; Vibration; Periodicals; Electronic journals; 620.205
• DOI: 10.1016/j.jsv.2017.11.001
• Languages: English
• ISSNs: 0022-460X

Abstract

Abstract: Identification of orbit responses can make the active protection operation more easily realize for active magnetic bearings (AMB) in case of touchdowns. This paper presents an identification method of the orbit responses rooting on signal processing of rotor displacements during touchdowns. The recognition method consists of two major steps. Firstly, the combined rub and bouncing is distinguished from the other orbit responses by the mathematical expectation of axis displacements of the rotor. Because when the combined rub and bouncing occurs, the rotor of AMB will not be always close to the touchdown bearings (TDB). Secondly, we recognize the pendulum vibration and the full rub by the Fourier spectrum of displacement in horizontal direction, as the frequency characteristics of the two responses are different. The principle of the whole identification algorithm is illustrated by two sets of signal generated by a dynamic model of the specific rotor-TDB system. The universality of the method is validated by other four sets of signal. Besides, the adaptability of noise is also tested by adding white noises with different strengths, and the result is promising. As the mathematical expectation and Discrete Fourier transform are major calculations of the algorithm, the calculation quantity of the algorithm is low, so it is fast, easily realized and embedded in the AMB controller, which has an important engineering value for the protection of AMBs during touchdowns. Highlights: We presents an identification method of the orbit responses during touchdowns. The axis displacement of the rotor is used to identify orbit responses. A small amount of calculation is done in the identification process. The presented algorithm is adaptive to the white noise.